Re: How to add a custom cell renderer to a Gtk::IconView

[Todor Todorov <ttodorov gmx net>]

I need to clarify. What I tried was:

Glib::RefPtr<Gtk::CellLayout> cl = Glib::wrap( GTK_CELL_LAYOUT( my_icon_view.gobj() ) );


And the error was: "Glib::wrap_auto_interface(): The C++ instance
(N3Gtk8IconViewE) does not dynamic_cast to the interface."


On 11/17/2009 10:47 PM, Todor Todorov wrote:
> Hello list,
>
> I encountered the following problem: Under Gtk+ it is possible to have a
> GktIconView and cast it to a GtkCellLayout via the GTK_CELL_LAYOUT(obj)
> macro. Then I could add a custom cell renderer and set attributes to it.
>
> Now I have implemented my cell renderer in C++/Gtkmm and would like to
> add it to my Gtk::IconView. And since the class does not provide a
> pack_start() functionality like TreeView, I would have to go and find my
> own way to do it...
>
> The first problem is that the IconView class does not inherit (in the
> traditional C++ way) from Gtk::CellLayout. Second, the
> reinterpret_cast<> did not work either. There is no function in the
> Gtk::IconView API that lets me convert to a CellLayout, or in the
> Gtk::CellLayout API to create it from an IconView... Third, I tried to
> do something like
>
> Gtk::CellLayout *cl = Glib::wrap( GTK_CELL_LAYOUT( my_icon_view.gobj() ) );
> cl->pack_start( renderer, false );
> cl->add_attribute( renderer->property_blah(), columns.blah );
> ....
>
> While it compiles, the application crashed with a reinterpret_cast
> failure reported. The only thing that worked so far was to take my Gtk+
> implementation of the renderer, add it to my project and create a
> GtkIconView, cast it to GTK_CELL_LAYOUT, add the renderer with
> properties, and at the end wrap it into a Gtk::IconView and work from
> there as it were pure Gtkmm.
>
> I wonder though, is this the best way? I would like to not handle Gtk+
> objects directly in my code. Can anyone make a suggestion as to how to
> add a custom cell renderer to a Gtk::IconView in a "best practice"
> approach? Your help and time are greatly appreciated.
>
> Kind regards,
> Todor
> _______________________________________________
> gtkmm-list mailing list
> gtkmm-list gnome org
> http://mail.gnome.org/mailman/listinfo/gtkmm-list
>
>